MEMSaccelerometre

MEMS accelerometer, sometimes written MEMS accelerometre, is a compact sensor that measures acceleration using microelectromechanical systems. It typically detects acceleration along one or more axes by a proof mass suspended on springs within a silicon substrate. Modern devices integrate signal conditioning and often a digital interface, enabling direct connection to microcontrollers and processors.

Principle: In capacitive MEMS accelerometers, a movable proof mass changes the capacitance between adjacent plates as it shifts under acceleration. In piezoresistive variants, stress on a sensing element causes a change in electrical resistance. Most devices are differential, improving noise and drift performance. Many MEMS accelerometers are three-axis, providing simultaneous measurements along orthogonal directions.

Manufacturing and packaging: Manufacturing uses silicon micromachining (surface and bulk), allowing mass production at low cost. After release, the sensor is packaged and sealed to prevent contamination; many devices include an on-board application-specific integrated circuit, an analog-to-digital converter, and interfaces such as I2C or SPI. 3-axis types are common, enabling measurement of acceleration in three perpendicular directions. Temperature compensation and calibration are often implemented to improve accuracy.

Performance and interfaces: Key figures include dynamic range (typical consumer devices ±2 g to ±16 g; higher ranges exist for industrial and automotive applications), bandwidth from a few hertz to several kilohertz, noise density, resolution, and bias stability. Temperature sensitivity and aging effects are addressed through calibration and compensation. Some devices support self-test, interrupts, and configurable digital outputs.

Applications: MEMS accelerometers are used in smartphones for orientation and gesture recognition, wearables for activity tracking, drones and robotics for inertial measurement, automotive systems for airbag deployment and stability control, and industrial equipment for vibration monitoring and condition assessment.

History and market: MEMS accelerometers emerged from silicon micromachining developments in the late 20th century. Major manufacturers include Bosch, STMicroelectronics, Analog Devices, InvenSense, and Kionix. The market has grown with mobile devices, automotive safety, and IoT applications.